Method of and apparatus for grinding and polishing materials



Feb. 28, 1933. I L. E. HOWARD 1,899,463

METHOD OF AND APPARATUS FOR GRINDING AND FOL ISHING MATERIALS FiledMarch 26, 1950 Patented Feb. 28, 1933 uu rso STQATESPATENT OFFICE;

LESLIE E. HOWARD, 0F LOOKPORT, NEW YORK, ASSIGNOR 1'0 SIMONDS SAW ANDSTEEL COMPANY, OF FITGHBURG, MASSACHUSETTS, A- CORPORATION OF MASSA-GIHUSETTS METHOD or AND APPARATUS FOR en'minne AND POLISHING MATERIALSApplication filed March 26, 1930. Serial lTo. 439,047.

This invention relates to the art of abrad fact that the abrasivematerial is'not glued or otherwise affixed to the face of the wheel, butloose abrasive is supplied asa powder between the wheel and the surfacebeing treated. When the abrasive is supplied in proper quantities anduniformly distributed across the face of such a wheel the work is moreuniform and in general more satisfactory than that obtainable with othertypes of wheels having abrasive surfaces which deteriorate with use.Heretofo-re it has been very difiicultto effect a good distribution ofabrasive even over the face of a wheel operating on the upper surface ofa piece of stock, while it has been practically impossible to effectproper control and distribution of abrasive over a wheel operating on anunder or abrading both the upper and lower surfaces of a piece of stock;to provide apparatus for 7 these purposes of rugged and durable and yetsimple and efficient construction, consist ing of new parts which arealso relatively inexpensive to manufacture; and also to pro videapparatus ofthis character having an improved construction andarrangement of parts.

In the drawing:

Figs. land 2 are respectively diagrammatic side and end views of oneembodiment of the invention; and Figs. 3 and 4: are respectivelydiagrammatic side and end views showing another embodi- -ment of theinvention. 7 e

In Figs. 1aand'2, upper and lower polishing wheels '11 and '12, aremounted upon arbors 13 and 14 which are supp'ortedfo-r rotation inbearings (not shown) in the usual manner; Thesewheels are spacedtOTBCBlVl-l a piece of stock 16 for simultaneously polishing theupperand lower surfacesof the stock,

the. latter being'preferably moved against the travel of thewheels.Arcuate guides 17 and 18 which are preferablychannel-shaped in crosssection extend circumferentially about the wheels. A portionfof theperiphery ofeach wheel is disposed within the sidewalls of these guidingmembers, preferablybeing spaced slightly from the side walls. The guides17 and 18 are also arranged so that the base of the channel is spacedfrom the face of the wheel at distances which dibeneath the hopperisclosed by end and hot tom walls 22, 23. An opening or slot 24 extendsthrough the bottom wall 23 transversely across the face of the wheel 11.This slot and hopper 21 are located well to the right of the center ofthe wheel 11 so that under some conditions material may pass from thehopper directlythrough the slotahd' be discharged from the apparatus/Thelower guide 18 has a similar 'slot 26 which likewise extendstransversely across the face 'ofthe wheel 12 and isdisposed in thelowest portion of the guide 18. Abrasive material is supplied from ahopper 27 conveniently located above the polishing wheels, and chutes orpipes 28 and 29 conduct abrasive material re- 9 ranged in the samemanner as described with respect to Fig. 1 and channel-shaped guides 31and 32 are also spaced about the wheels in the same way that the guides17 and 18 are disposed in Figs. 1 and.2. The guide 32 has a slot 33extending transversely across the f face of the wheel at the lowestportion of this guide. The upper guide 31 has a bottom Wall 34 extendingfrom the upper end of the guide toward the face of the Wheel. The endsing the excess abrasive falls harmlessly through the slots and, ofcourse, does no dama e.

The apparatus shown in Figs. 3 and 4 op- 5 36"and 37 ofthe guides areopen. Abrasive---erates in the same general manner as that material issupplied to the -apparatus from a hopper 38 through a formation pipe 39hav- 7 ing a conneotiontl to the side wall of the I i upper guideadjacent the ope'n'e nd 36the1'eof and having a connection 42to the sidewall of the lower guide adjacent the open end 37 thereof, Air--jets areformedwithin the formation pipe 39 by air issuing from small pipes ornozzles 43 "and-tfwhich are efiec-. Y tive for translating abrasivematerial from 1i formation pipe 'throu'gh 'the connections 41 and 42into thempper and' lowerguides.' l These'jetsare controlled by' val-'ves46 and: 17 "andare supplied with'air under pressure from 5 20' pipe 4:8.I I "'1' In the operation of theapparatus-shown in Figsll and 2;abrasive material: is permitted 'todescend continuously from thehopper'27 I throu'gh'th'e pipes '28 and QQ-being conducted-- in 'this' mannerto the-convergent qp'a'ssage's formed"between'tlre' guides 17 and: 18,and thewheels with which these "guidesare assol 1 ciatedr 'When thesewheels are: operating. in thedirection indicated by the arrows,thew-indage,-that is, the'-friction--of the face of the wheel with theair'envelopingthi'sportion "of thewheehsets up acur-rent which is efiiecdisclosedlin Figs. 1 and 2, but in this instance abrasive descendingfrom the hopper 38 through the formation pipe 89 is translated throughthe--coi1nections 4:1-{ln d-42 by in]ecting air across the pipe '39- andthrough these connections. This -air is': preferably delivered at acomparatively loW pressure and sufficient"volume through"the air jets 43and Mtoefiiect the desired distribution transversely of the wheels. Theapparatus shown-in thesesviews. is especially-adapted for bufii-ng:where. the. abrasiveis extremely fine,-or'the- Wheel facesare wide, .orboth. It is also a valuable applicationrwhere it is desired to-run veryWide. wheels, :as for example, wheelsihavlngfacestlfzeinches and over,with abrasives of polishing sizes as distinguished. from .bufiingabrasive. sizes. These fine abrasives tend. tocakeanddo not flow freelyas larger material will. ,Theiair jets43 are eflectivein breaking upamass of ithis=abrasive and distributing. it uniformly across the faceof. a wheel. :By'regulating theamount of airzpassing. from the air jetswith respect to the amount ofabrasive falling down the formation pipe39.,just the right amount of abrasivemay.bedistributed across *tive-t'o-distribute abrasive material-transthe face. ofthe endopeningstof the.upper A versely'a'oross the face of the'wheel: and .also F *to conveythis material bircuniferantial-ly about the face-to the-surface of theStockbe ing-treated. -The guidem'embers l'i and 18 5" keep'the -abrasivematerial in this current J and a'lsoths'e' membersareeifeotive due tothe I icorivergene ofthe passage or-air duct niai- !fiteriall-y-todncrease the velocity: oflthe-air *-stream a's"thestockisapproached* This-ar rangeme'nt'provides a good distribution and lsuch exact control that the -abradingor pols ishing done by'the topwheel-and the bottom whee-lis alike: -*When the :wheelsare;not-operati-ng material: delivered through the pipe r 28 to thehopper 21 is'allowed to :pas srthrough theslot'24'and'to-escape from theguide 17 in this-manners *Thisds a:- desirablefeature as "*itav'oids thepossibility dfzhaving this material'collect'betweenthe lower-endof theguide 'l'l' -and' the face oft-he wheel, 'for-it' will be appa-rentthatsuch anoccurrence' might result in sprungarbo'rs 'andgeneral damagewhen 1r 7 the polis'liingwheels were'started due to their being toogrea'tiajsupply of abrasiv'e'on the strip, andpof' courseg tiarriedbetween the wheels.- Abrasive "ism-1S0 permitted-to escape. from'substantially the lowest'portion' of the guide 18 through the slot-26.IC- isfound that H whemthe polishing -wheels are running-at' 5! normalspeed the abrasive'is'carried 'by. the sl'ots 2 l 5 and'-'26 andpractically none falls 1., ofiwthrough while when thewheelszare standandlower. guides, and thismay beregulated so nicely .thattheamoimtof-abrasive is so small andso uniformly distributed that it appears morelike a..fog. or smoke than a stream or massof abrasive. Once within theinfluenceof-the moving. air set up by the rotation of therwheels, it israpidly'drawn into the opening between the periphery of the .wheelsandthe corresponding part of the easings or guides..-and brought to itspoint of applicationpreciselyas described with reference to Figs- 1 and2. .It will be observed thatthe formation. or delivery pipe 89 isdisposedfar enouglnto one side of the center of the upper. wheel so thatwhen this wheel is not revolving, such abrasive as may be blown in willdrop harmlessly to a pit providedfor this purpose, or a portion of itmay drop into the lower casingf82 and fall through the slot 33.. It willalso'be'apparentthat the delivery pipe 39 may be replaced by two pipessuch as the pipes 28'and 29, as shown in Figs. 1 and 2.

I claim:

1. The combination of-means providing a circumferentially extendingchannel, a polishing Wheel with a portion of itslperiphery disposedwithin the channel','-means for supplying abrasive to. the channelandmeans effective while the wheeltisfstationary for dischargingabrasive from the channel.

22. The. :combination with. 331% [polishing wheel, of an air ductextending circumferentially about a portion of the wheel, the face ofthe wheel being disposed within the duct, a conduit connected to theduct for supplying abrasive thereto, and fluid jets for deliveringabrasive through the conduit to the duct.

3. The combinatlon with polishing wheels spaced for polishing theopposite sides of a piece of stock disposed therebetween, of air ductsextending circuniferentially about each wheel, the face of each wheelbeing disposed within the duct associated therewith and spaced therefromto define a convergent passage about the wheel, the end of each ductbelng open at the larger end of said convergent passage, supply conduitsconnected to the larger end of each of saidconvergent passages, andfluid translating means for delivering abrasive through the conduits tothe ducts.

Signed by me at Lockport, New York, thls twenty-second 22d day of March1930.

LESLIE E. HOWARD.

